memcpy regression

Dear Christophe,

my MPC5200-based system stopped booting recently. I bisected the problem
to your commit below. If I revert that commit (on top of
807249d3ada1ff28a47c4054ca4edd479421b671 = v4.2-6663-g807249d), my
system boots again.

commit 0b05e2d671c40cfb57e66e4e402320d6e056b2f8
Author: LEROY Christophe [off-list ref]
Date:   Tue May 19 12:07:55 2015 +0200

    powerpc/32: cacheable_memcpy becomes memcpy
    
    cacheable_memcpy uses dcbz instruction and is more efficient than
    memcpy when the destination is in RAM. If the destination is in an
    io area, memcpy_toio() is normally used, not memcpy
    
    This patch renames memcpy as generic_memcpy, and renames
    cacheable_memcpy as memcpy
    
    On MPC885, we get approximatly 7% increase of the transfer rate
    on an FTP reception
    
    Signed-off-by: Christophe Leroy [off-list ref]
    Signed-off-by: Scott Wood [off-list ref]

Best regards,
-Michal Sojka